I. Field
The invention relates to a control system designed for the operation of surface blowout preventer (BOP) and diverter systems. More specifically, the unique design elements and employment methods incorporated within the control system that offer an improvement over conventional methods and designs.
II. Background
Blowout preventers (BOP) and diverter control systems incorporate the use of flow control and electrical components to deliver hydraulic fluid to rams, valves, seals, and other types of equipment for their operation. These systems also provide means of monitoring key factors measured during well control operations.
The systems feature two different modes of operation: local manual and remote automated. Flow control valves are used for guidance of hydraulic fluid from the control system to the end-devices (rams, valves, seals and other types of equipment). For local manual operation, the flow control valves may be manually actuated. Alternately (for remote operation) remote stations are employed to initiate electric solenoid valves to control air flow to the air driven actuators of the same flow control valves.
Piping and tubing materials (system rated working pressure of 3000 PSI) are used for the interconnection of flow control components. In conventional BOP and diverter control systems, large manifolds are installed for the interconnection of common fluid supply and return ports of flow control valves for functions of high volume requirements.
Additionally, the methods used to construct the piping system associated with such control systems involve custom-designed piping and tubing runs specially designed for each individual project. These piping systems include welding of components by means of butt and/or socket welds. This welded piping system is further tested to ensure that the integrity of the welds satisfy all third-party requirements. Further, tubing lines are installed for the interconnection of flow control valves for functions of low volume requirements. These valves are normally permanently attached to a function plate or mounted on the unit's skid frame. Furthermore, tubing connections are guided to individual pressure reading devices (including gauges, electric switches and transmitters) for the purpose of sensing pressure at key points. All of these specialized piping and tubing runs can significantly increase the cost of installing a given BOP and diverter control system.
Conventional diverter control systems provide means of delivering automated sequences when operating a Diverter Packer. A series of diverter functions are automatically actuated upon operation of the diverter packer by implementing an air-based logic sequence with the use of shuttle valves, air timers, and air piloted valves. This air-based control system further increases the cost and complexity of conventional systems.
Due to the harsh environmental conditions presented in drilling areas, conventional surface blowout preventer (BOP) and diverter control systems are designed to safely operate in harsh hazardous locations. The safe operation of such control systems within hazardous environments contributes to the selection of hazardous area-rated electric components. Conventional control system designs include the use of flameproof equipment as a preferred method of protection (as seen in the oil and gas industry). This hardened equipment again increases the cost, and bulk, of conventional systems.
For the reasons mentioned above, there is a need for a compact BOP and diverter control system that eliminates the need for many of the bulky components associated with conventional control systems, while at the same time being capable of operating in an intrinsically safe manner given the hazardous conditions.